<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>base</title>
</head>
<body>
    {% block header %}<h1>{{header}}</h1>{%endblock%}
    {% block body %}<p>{{body}}</p>{%endblock%}
    {% block footer %} <div>copyright</div> {% endblock %}
</body>
</html>